This research proposal deals with the following question: when a person has witnessed some unusual event such as a crime or an accident, how can complete and accurate information best be obtained about that event? The research focuses specifically on the influence that questions asked subsequent to an event have (1) on the answers to those questions, (2) on the answers to subsequent questions, and (3) on the witness's memory for the incident he has experienced. A major premise is that questions asked subsequently to an event can contain new information which becomes integrated into the original memory, causing a reconstruction of the witness's memory for the event. The framework for a theory of memory for complex, largely perceptual, experiences which includes a reconstructive mechanism, is presented. In all oo the proposed experiments, subjects will view a film or series of slides depicting a complex visual event. At appropriate intervals, the subjects will be asked questions about events occurring in the films or slides, the purpose of which will be to supply additional information to the subject in subtle ways. After a period of time, the subjects will be retested to assess the effects of the newly introduced information. All of the proposed experiments share the common goals of refining and extending theoretical formulations about reconstructive processes of human long-term memory, while simultaneously probing ways to obtain more accurate testimony from a witness.